Connecting device for attaching a structural component, a shielding component in particular

ABSTRACT

1. Connecting device for attaching a structural component, shielding component in particular  
     2. In a connecting device for attaching a structural component, a shielding component ( 1 ) in particular, to at least one associated support part ( 9 ) by means of at least one clamping part ( 11 ) which can be moved with at least one clamping surface ( 15 ) into contact with the support part ( 9 ), the clamping surface ( 15 ) is connected to an attachment arm ( 13 ) of the clamping part ( 11 ) which can be advanced non-positively onto the support part ( 9 ) by a feed means ( 23, 27 ).

The invention relates to a connecting device for attaching a structural component, a shielding component in particular, to at least one associated support part by means of at least one clamping part which can be moved with at least one clamping surface into contact with the support part.

While the heat such as that evolved by a high-economy, performance-optimized diesel engine for example, can be very low on the cylinder crankshaft housing, this in no way applies to “hot zones” such as in manifolds, turbochargers, catalytic converters, etc. As a result of the increasingly compact design of engines, components which are not thermally “compatible” are coming to be in ever closer proximity. Hence it is necessary to use so-called shielding components such as heat shields to protect adjacent heat-sensitive assemblies, such as sensors, fuiel lines, pressure cells, body parts, and so forth. The situation is also exacerbated by the compact structure in that the high packing density of the assemblies constricts the cooling air flow in the engine compartment. Noise abatement measures can also contribute to this problem. For example, under certain circumstances plastic floor plates having the function of reducing the level of sound emerging from the engine compartment to the roadway can produce effective insulation whereby heat is trapped in the engine compartment. Because of their high surface temperatures in some phases, catalytic converters are among the heat sources which may necessitate the use of protective shield barriers. A typical example is that of design measures such as positioning the catalytic converter in the immediate vicinity of the manifold. This design principle, which performs the function of rapid heat-up of the catalytic converter, and thus of reducing emissions in the cold start phase, shifts a major source of heat into the engine compartment where a considerable number of assemblies are crowded in a tight space. Another reason for the growing importance of shielding components such as heat shields is the trend toward use of thermoplastics. Light and economical materials with their exceptional moldability are rapidly becoming common in the engine compartment, but require special attention with respect to ambient temperatures generated at the application site in connection with other heat-generating engine parts (New materials and Development Tools for Protection from Heat, in MTZ December 2001, Vol. 72, pp. 1044 et seq.).

In addition to the thermal loads to which structural components such as shielding components in particular are exposed in operation, there are mechanical loads, especially due to vibrations which are transmitted by way of the support parts to the structural components. In view of these loads, special demands must be imposed on the connecting devices which keep these structural components in position on the pertinent support parts. Conventional connecting devices of the prior art call for spring clamps with a certain pretensioning (clips) which are clamped by way of stud pins or the like, but also by way of entire components, for example solenoid switches of generators, or by way of exhaust manifolds. The clamping force or holding force results from the choice of the spring material and the structural design of the pertinent springs. As has been found, however, especially when the pertinent structural component is a hot component, there is the danger that fatigue phenomena will occur in the spring material; this is the case to an increased degree when operation-induced vibrations are added. Reliable attachment of the pertinent structural components by means of the known connecting devices is therefore not ensured.

On the basis of this prior art, the object of the invention is to make available a connecting device which ensures especially secure attachment of the pertinent structural components even under high continuing thermal and mechanical loads.

This object is achieved by a connecting device with the features of claim 1 in its entirety.

While in the prior art only the spring force of the clamps or clips is available as the clamping force on the pertinent support part, so that as a result of the aforementioned fatigue phenomena and vibration loads the structural component may be displaced or even fall off, according to the characterizing part of claim 1 the invention calls for non-positive advance of an attachment arm of the clamping part by a feed means. The pertinent structural components are therefore clamped as claimed in the invention with a clamping force effected by the feed means in addition to the forces of elasticity or independently of the forces of elasticity so that high operating reliability of attachment of the structural component is achieved.

Especially simple and reliable attachment arises in exemplary embodiments in which the feed means has a locking screw, by means of the screwing force of which the clamping part can be tensioned against the pertinent support part.

Preferably for clamping two support parts located at a distance from each other the clamping part has two attachment arms which extend in the direction opposite each other away from the feed means which is shared by the two arms. In these embodiments the attachment of the pertinent structural component is especially simple, since only one feed means, for example in the form of a locking screw, need be actuated to effect locking to several support parts, so that in many instances it is sufficient for the overall mounting of the structural component if a single locking screw is tightened.

In especially advantageous embodiments a mounting part which is connected to the structural component in the respective clamping region forms second clamping surfaces which interact with the pertinent clamping surfaces of the clamping part and against which the pertinent support parts can be pressed by means of the associated first clamping surfaces of the clamping part, and the clamping part can be advanced in the direction to the mounting part by the screw force of the locking screw. If in this connection the configuration is such that when the clamping part is advanced in the direction to the mounting part, when the locking screw is being tightened the required clamping force which is desired for secure attachment is applied to the support parts tensioned between the clamping surfaces even before the clamping part is advanced by the locking screw up to contact with the mounting part, then the resulting clamping force is dependent on how closely the clamping part has approached the mounting part by tightening the locking screw. By more or less strong tightening of the locking screw, i.e., the clamping part more or less approaching the mounting part, the clamping force can be adjusted at will.

This embodiment also makes it possible to execute the clamping part as a comparatively rigid component, for example in the form of a clamping strip with a reinforcing bead. The clamping force is determined here essentially solely according to the screw force of the locking screw.

When the required theoretical clamping force on the clamped support parts is achieved in the mounting process before the clamping part is advanced by the locking screw up to contact with the mounting part, there arises the further advantage that after a correspondingly long operating time has passed, if possibly service measures must be carried out, the locking screw can be retightened to move the clamping part closer to the mounting part. If after extended operating times, due to metal fatigue for example, a certain relaxation of the clamping force should have occurred, the original desired clamping force can be restored by this retightening.

With respect to ease of mounting it is especially advantageous if one of the arms of the clamping part is lengthened beyond the area of the pertinent clamping surface by an extension, and this extension is connected to the mounting part at an attachment point. This yields a mounting unit in which in the premounted state the clamping part is already captively held on the associated structural component before the locking screw is attached to complete the mounting unit.

If in this connection the clamping part is designed as a stiff component, the extension between the attachment point and the transition area to the clamping surface of the adjacent arm has a spring element which permits essentially unhindered feed motion of the clamping part onto the support parts.

The subject matter of the invention is also a structural component, a shielding component in particular, with a flat operating part and a mounting part connected to it, as claimed in the invention the mounting part being a component of a connecting device according to one of claims 1 to 8 for attaching the structural component to at least one support part.

The invention will be detailed below using the drawings.

FIG. 1 shows a perspective oblique view, looking at the inside of a structural component in the form of a metallic shell part which forms a shielding component, provided with a connecting device according to the prior art for attaching the structural component to the support parts in the form of cylindrical sleeves;

FIG. 2 shows a perspective view, looking at the inside of a structural component in the form of a metallic shielding component in the form of a partial shell, provided with one exemplary embodiment of a connecting device as claimed in the invention, and

FIG. 3 shows a perspective oblique view of what is shown in FIG. 2.

FIG. 1 shows a structural component in the form of a shielding component designated as a whole as 1. It has the shape of a partial metallic shell with an arched operating part 3, the interior of which is shown in FIG. 1, and which is intended as a heat shield or noise-insulating element for the shielding of the corresponding zones or components. The operating part 3 which is provided with arched stiffening beads 5 which increase the dimensional stability for its attachment to the associated support parts has a connecting device according to the prior art which in the manner conventional in these known devices has clamps of spring steel or spring clips 7 which due to their spring force with clamping surfaces which are located on the inside of their clamp legs clamp the pertinent support parts which are round sleeve bodies 9 in the illustrated example. The sleeve bodies 9 which form the support parts can be penetrated by stud bolts which are not shown, for example in conjunction with cylinder heads, engine blocks or exhaust manifolds of an internal combustion engine or can be connected in some other way to a supporting structure. Likewise the spring clips 8 could form a direct clamp connection on the stud bolts.

As already mentioned, in the designs according to the prior art shown in FIG. 1, there is the danger that relaxation of the force of elasticity of the clip 7 will occur due to fatigue phenomena and/or thermal loads in operation, so that operating reliability leaves something to be desired. The greatest attainable clamping force is limited at any rate to the spring force of the clips 7.

FIGS. 2 and 3 show one embodiment of the connecting device as claimed in the invention for attaching a structural component, in which it is likewise a shielding component designated as a whole as 1 of the type shown in FIG. 1 in conjunction with the conventional connecting device. As is FIG. 1, the shielding component 1 forms a flat operating part 3 which forms the actual shield wall and in which there are reinforcing beads 5 to increase the structural strength and to optimize the vibration behavior; this is also important with respect to noise insulation. As in the example from FIG. 1 which corresponds to the prior art, the circular cylindrical sleeve bodies 9 form the support parts to which the shielding component 1 can be attached and which extend parallel to each other at a distance to each other.

Instead of using the spring clips 7 shown in FIG. 1, in the invention there is at least one clamping part 11 which has an attachment arm 13 for each support part to be clamped, that is, here each sleeve part 9. Each attachment arm 13 is shaped such that in its end area it forms a first clamping surface 15 which surrounds a peripheral section of the respective sleeve body 9 which is to be clamped and presses it against a second clamping surface 17 which is located on a mounting part 19. The mounting part 19 is connected to the operating part 3 of the shielding component 1, in the example shown here in the form of an edge strip which is integral with the operating part 3. This strip is essentially flat, except for the reinforcing bead which runs along the edge strip, and arches which form the clamping surfaces 17. The main plane of the edge strip which forms the mounting part 19 runs at a distance parallel to the connecting line between the cylinder axes of the cylindrical sleeve bodies 9 and parallel to these cylinder axes.

As FIGS. 2 and 3 show, in the illustrated exemplary embodiment the clamping part 11 has two arms so that two attachment arms 13 proceeding from a central area 21 extend in opposite directions to the sleeve bodies 9 to be clamped. In the central area 21 there is a feed means for producing a feed movement of the attachment arms 13 against the sleeve bodies 9 in order to allow a clamping force to be created on them. In the illustrated embodiment the feed means is formed by a locking screw configuration which contains a locking screw 23 which extends through the mounting part 19, having a screw head 25 which is accessible on the outer side of the mounting part 19, and a rivet nut 27 which is riveted in the central area 21 of the clamping part 11 on one opening thereof.

As FIG. 2 clearly shows, when the locking screw 23 has been tightened to such an extent that on the clamping surfaces 15 and 17 the clamping force of the desired and necessary strength acts on the sleeve bodies 9, there is a distance between the clamping part 11 and the inside of the mounting part 19. This means that when the locking screw 23 is tightened more vigorously so that the distance between the central area 21 of the clamping part 11 and the mounting part 19 is reduced, the clamping force produced by the arms 13 by way of the clamping surface 15 is increased. When the clamping part 11 with the attachment arms 13 is made as a comparatively stiff component, for example with a reinforcing bead 29 which runs in the longitudinal direction (FIG. 3), the strength of the clamping force is essentially directly related to how strongly the locking screw 23 is tightened, i.e., how closely the clamping part 11 has approached the mounting part 19.

If, as shown in this example, the clamping part 11 on the end of its one attachment arm 13 is lengthened by an extension 31 and the latter is connected on the end side at an attachment point 33 to the edge part of the shielding component 1, there is the advantage that when the connecting device is premounted on the shielding component 1, before the locking screw 23 is used, the clamping part 11 is already captively locked. Since before the locking screw 23 engages the rivet nut 27 of the clamping part 11, the clamping part 11 can be raised relatively far off the mounting part 19, the insertion of the sleeve bodies 9 between the clamping surfaces 15 and 17 is also facilitated during mounting.

In order to prevent the feed motion produced by the locking screw 23 from being hindered in a comparatively rigid construction of the clamping part 11 in spite of attachment of the extension 31 to the attachment point 33, it is advantageous to provide a spring configuration 35 on the extension 31 between the attachment point 33 and the transition to the end of the attachment arm 13. The illustrated exemplary embodiment is a reduced-width point on the extension 31 which forms a shaft shape raised to the inside. This shaft acts both as a spring element to ensure comparatively free mobility of the facing attachment arm 13 of the clamping part 11, and also as a compensation element for possible thermally induced deformations, such as elongation and stretching. It is within the scope of the invention to distribute the clamping force applied by the spring configuration 35 between the two sleeve bodies 9. 

1. Connecting device for attaching a structural component, a shielding component (1) in particular, to at least one associated support part (9) by means of at least one clamping part (11) which can be moved with at least one clamping surface (15) into contact with the support part (9), characterized in that the clamping surface (15) is connected to an attachment arm (13) of the clamping part (11) which can be advanced non-positively onto the support part (9) by a feed means (23, 27).
 2. The connecting device as claimed in claim 1, wherein the feed means (23, 27) has a locking screw (23), by means of the screwing force of which the clamping part (11) can be tensioned against the pertinent support part (9).
 3. The connecting device as claimed in claim 1, wherein for clamping two support parts (9) located at a distance from each other the clamping part (11) has two attachment arms (13) which extend in the direction opposite each other away from the feed means (23, 27) which is shared by the two arms (13).
 4. The connecting device as claimed in claim 2, wherein a mounting part (19) which is connected to the structural component in the respective clamping region forms second clamping surfaces (17) which interact with the pertinent clamping surfaces (15) of the clamping part (11) and against which the pertinent support parts (9) can be pressed by means of the associated first clamping surfaces (15) of the clamping part (11) which can be advanced in the direction to the mounting part (19) by the screw force of the locking screw (23).
 5. The connecting device as claimed in claim 3, wherein one of the arms (13) of the clamping part (11) is lengthened beyond the area of the pertinent clamping surface (15) by an extension (31), and wherein the extension (11) is connected to the shielding component (1) at an attachment point (33).
 6. The connecting device as claimed in claim 5, wherein the clamping part (11) is made as a stiff component and wherein the extension (31) between the attachment point (33) and the transition area to the clamping surface (15) of the adjacent arm (33) has a spring element (35) which permits feed motion of the clamping part (11) onto the support parts (9).
 7. The connecting device as claimed in claim 6, wherein the extension (31) is bent relative to the arms (13) of the clamping part (11) and adjoining a correspondingly bent part of the mounting part (19) is connected to the latter.
 8. The connecting device as claimed in claim 3, wherein the respective support parts are formed by round bodies such as stud bolts or sleeves (9) and wherein the clamping part (11) between the attachment arms (13) has a straight central part (21) which is engaged by the locking screw (23), and curved arms (13) proceeding from it which form the clamping surfaces (15) which are matched to the round shape of the support parts.
 9. Structural component, a shielding component (1) in particular, with a flat operating part (3) and a mounting part (19) connected to it, wherein the mounting part (19) is a component of a connecting device as claimed in claim 1 for attaching a structural component to at least one support part (9).
 10. The structural component as claimed in claim 9, wherein the mounting part (19) is made integral with the operating part (3).
 11. The structural component as claimed in claim 10, wherein the operating part (3) has the shape of an arched shell part which is bordered on at least one edge by a flat edge strip which is bent relative to the shell shape, which is straight over a large part of its length, and which forms a mounting part (19). 